When an impact tool such as an electric hammer or an electric drill is used, the reaction of a striking operation is transmitted through a grip to a user. Thus, this may give vibration fatigue to the user or may cause joint disorder.
Therefore, there has been proposed a method in which a mechanism for reducing vibration generated during the striking operation is provided on the impact tool to damp an impact force that is generated during the striking operation.
For example, JP-B-4461046 discloses a structure in which a grip part is relatively rotatably joined to a main body of a working tool through a rotating shaft at one end side in an extending direction of the working tool, and is joined thereto through an elastic body and a vibration damping part at the other end side in the extending direction thereof. With such a structure, the grip part relatively rotates to perform a vibration absorbing action and simultaneously absorb a displacement difference by the elastic body. Further, it is believed that the absorbing action by the elastic deformation of the elastic body and the damping action of the vibration damping part may effectively reduce vibration.